Cutter head for dry shaver having additional cutting means

ABSTRACT

1,184,114. Dry shavers. G. HEYEK. 6 April, 1967 [6 April, 1966], No. 15915/67. Heading B4B. The cutter head of a dry shaver comprises upper and lower foil cutters 1, 2 and a tension bridge 4 pressing the lower cutter against the upper cutter, bent side portions 1a of the upper cutter being held in a frame 3 and bent-out edge portions 2a of the lower cutter being held in openings 4a of the tension bridge. The lower cutter is reciprocated with respect to the upper cutter and has rectangular openings 2c arranged to co-operate with diamond-shaped openings 1c in the upper cutter. The upper cutter has openings 1d and the opposite edge portions of the lower cutter are formed as comb cutter parts 2d. In a modification, the bent side portions 1a Fig. 2 of the cutter foil 1 extend at an acute angle to oblique flange portions 3a of a head carrier 3b. Springs 5 engage the tension bridge 4 to urge the lower cutter against the upper cutter.

G. HEYEK 3,436,822 CUTTER HEAD FOR DRY SHAVER HAVING ADDITIONAL CUTTING MEANS April 8, 1969 Filed April 5, 1967 INVENIOR GI-lzakcZ He ek I ATTORNEYS G. HEYEK April 8, 1969 CUTTER HEAD FOR DRY SHAVER HAVING ADDITIONAL CUTTING MEANS Filed April 5, 1967 Fig. 20

Gekzzza ml gg/ a ATTORNEYS G. HEYEK April 8, 1969 CUTTER HEAD FOR DRY SHAVER HAVING ADDITIONAL CUTTING MEANS Sheet Filed April 5, 1967 mvmon A52 111' H y K ATTORNEKS United States Patent US. Cl. 30-34.1 1 Claim ABSTRACT 6F THE DISCLOSURE A flexible lower cutter blade is movable in a cutting direction relative to a flexible upper cutter blade and resiliently urged against the same. Supporting means engage at least one of said blades adjacent to opposite edge portions thereof to apply opposing forces to said edge portions whereby an arched shape is imparted at least to a portion of each of said blades. The radius of curvature of each of said arched portions at its vertex is at least twice the rise of said arched portion. The contours of said arched portions, when viewed in said cutting direction, are substantially congruent. Said arched portions are substantially coextensive with the area of contact between said blades. To this end, the upper blade has an edge portion which is angled toward the concave side of the upper blade and the arched portion of the lower blade terminates short of the angled edge portion of said upper blade.

This invention relates to a cutter head for dry shavers, which cutter head comprises upper and lower, arched, flexible cutter blades, at least one of which is held in its arched shape by supporting forces, which act in mutually opposite directions adjacent to opposite edge portions of the blade. In these cutter heads, the lower blade is resiliently urged against the upper blade and is movable relative to the latter in the cutting direction.

In known cutter heads of this type, the upper blade has a large rise and the lower blade has generally a smaller radius of curvature so that the two blades can conform to each other in curvature only within a limited contact area. As a result, the effective cutting area of the cutter head is also limited. Those portions of the blades which lie outside the cutting area have only a supporting function. More particularly, such portions of the blades cannot be utilized as cutting combs.

It is an object of the invention to avoid the abovedescribed disadvantages and to improve a cutter head of the type described first hereinbefore in such a manner that virtually the entire arched portions of the two cutter blades can be used for cutting purposes and the edge portions of the contact area may be used as cutting combs, where this is desired.

According to the invention, this object is accomplished in that the rise of the arched blades is equal to or smaller than one half of the radius of curvature of the cutter blades at the vertex of the arch, and the contours of the arched surface portions of both cutter blades, when viewed in the direction of movement of the lower blade, are almost congruent and substantially coextensive with the contact area between the cutter blades, as the upper blade is angled at its edge portion toward its concave side and the lower blade terminates or is also angled close to the angled portion of the upper blade.

It is essential for the purposes of the invention that the two cutter blades when viewed in the direction of movement of the lower blade have virtually congruently curved surface portions, which are urged into contact with each other by spring pressure so that the entire contact area can actually be used for cutting purposes. This is ensured by a relatively small curvature of the two blades so that a contact with the skin on a much larger area is ensured in the use of the dry shaver, and by the fact that at least the upper blade has an angled edge portion and the lower blade terminates or is also angled at the angled edge portion of the upper blade.

To avoid a requirement for close manufacturing tolerances, it is preferred within the scope of the invention to hold only one of the two cutter blades directly in the described arched cross-sectional shape and to urge the other cutter blade against the first-mentioned blade to conform to the curvature thereof.

If the upper blade is held directly in arched shape, it will be recommendable to secure the angled portions of the upper blade to a supporting frame or the like, which is secured to a removable part of the cutter head or to the shaver housing.

On the other hand, if the lower blade is to be held directly in arched shape it may be provided with tie webs, which act at points that are disposed close to the edges of the arched portion.

The cutter head according to the invention will be of special advantage if the two cutter blades form cutting sieves as well as cutting combs. Cutting combs may be formed at the edges of the arched portions of the upper and lower blades because both blades contact each other as far as to the edges of their arched portions and can perform a cutting action at said portions.

As at least one of the two blades is angled at the edge of the arched portion, the perforations in the cutter blade or blades may extend across the bend line of the angled portion, so as to form a cutting comb.

The invention is applicable to cutter heads having a reciprocable or rotary lower blade. In the first case the two cutter blades are cylindrically curved. In the second case they are curved in accordance with a surface of revolution having an axis which extends through the vertex of the arch.

In cutter heads having a rotary lower blade, the same may be formed by equally angularly spaced blade sectors, which extend substantially radially and in the arched surface.

A desirable cutting action will be obtained within the scope of the invention if one of the two cutter blades has cutting edges extending at least approximately at right angles to the direction of movement of the lower blade, and the other cutter blade has rhombic apertures, in which the longer diagonal extends in the direction of the cutting edges of the first-mentioned blade.

Further features and developments of the invention will become apparent from the following description of illustrative embodiments shown on the drawings, in which:

FIGS. la to 18 show a first embodiment of the invention comprising a reciprocable lower blade.

FIG. 1a illustrates the essential parts of the cutter head. Parts are broken away in this figure to expose underlying parts.

FIG. 1b shows the upper blade,

FIG. 1c the lower blade, and

FIG. 1d the tie web of the lower blade of FIG. la, all in the same perspective view as in FIG. 1a.

FIG. 12 is a transverse sectional view showing the cutter head of FIG. la.

FIG. 2 is a transverse sectional view similar to that of FIG. 12 and shows a modification of the first embodiment.

FIG. 2a illustrates a detail of this modified embodiment.

FIGS. 3a to 30. show a further embodiment having a rotary lower blade.

FIG. 3a is a partly sectional view illustrating the overall construction of the cutter head,

FIGS. 3b and 3c correspond to FIGS. 1b and 1c, respectively, and

FIG. 3d is a transverse sectional view showing the cutter head.

FIGS. 4 and 5 show modifications of the embodiment of FIG. 3.

FIG. 6 is a top plan view showing a portion of the two superimposed cutter blades and illustrates a preferred design of the perforations of these blades.

The cutter head having a reciprocating lower blade shown in FIGS. la-le comprises an upper cutter blade 1 and a lower cutter blade 2. According to FIG. 1b, the cutter blade 1 is angled at its two opposite edges. The angled edge portions 1a of the blade are formed with apertures 112, by which the blade is hooked on noses 3a, which are formed on a supporting frame 3 of the cutter head and shown in FIG. 1a. The lower edges of the blade may engage in hooks 3a provided on the supporting frame 3. Thus, the angled side portions in of the blade 1 are retained on the frame 3. As the inside width of the frame 3 is less than the width of the blade 1, the latter is slightly arched. The cutter blade 1 has rhombic perforations 1c on its main surface and rhombic perforations 1d on its bent line, which are perforations only partly illustrated.

As is apparent from FIG. 1a, the lower cutter blade 2 extends only over the arched portion of the blade 1. The opposite edges of the blade 2 form cutting combs 2d. The main portion of the blade 2 is formed with rectangular apertures 20. Hooks 2a are struck out from opposite edges of the blade 2 and engage in holes 4a, which are formed in a tie web 4 and shown in FIG. 1d. When the hooks 2a of the blade 2 are inserted in the holes 4a of the tie web 4, the blade 2 is arched. By means of the web 4, the arched lower cutter blade '2 is urged against the upper cutter blade 1 so that the latter conforms exactly to the curvature of the cutter blade 2. The drive motor, not shown, acts in usual manner on a driver 4b, which is provided on the tie web 4. This motor imparts to the lower blade 2 a reciprocating movement relative to the upper blade 1.

It is seen that the two blades 1, 2 contact each other throughout their arched portions so that the entire contact area, which is provided with perforations 1c and 2:: throughout, can be utilized as a cutting surface. At the edges of the arched contact area, the cutting combs 2d of the lower blade 2 cooperate with the perforations 1d which extend across the bend line in the upper blade 1 so that a comblike cutting action is obtained. The purpose of the side cutter is for use to cut the long hair and also sideburns and the like.

The embodiment shown in FIG. 2 is substantially like that described with reference to FIG. 1 with the difference that the angled side portions 1a of the cutter blade 1 are not held in a frame but extend at an acute angle to inclined flange portions 13a of a head carrier 13b and are secured to the latter. This arrangement improves the accessibility of the cutting combs 1d, 2d at the angled edge portions of the upper blade 1. The tie web 4 of the lower blade 2 is engaged by curved leaf springs 5, the lower ends of which bear on the head carrier 13b and can roll on the same. The springs 5 urge the lower blade 2 against the upper blade 1.

FIGS. 3a to 3d illustrate the use of the invention in a cutter head which comprises a rotary lower blade. In this case the upper cutter blade 1', provided with apertures 1c and the cutting comb I'd, as well as the lower blade 2' are arched according to a surface of revolution. For this purpose, the upper blade 1 is angled twice at its edge and i s gripped in a ring 3, which may be provided with a flangelike projection 3'c, which embraces the angled portion 1a of the cutter blade 1' and bears on the edge of the blade so as to cause the same to arch.

The lower blade 2 shown in FIG. 3b has the same contour as the arched surface of the upper blade 1' but consists, e.g., of three radial sectors 2'11, 2'1), 2'0, which are equally angularly spaced. The sectors Za, Zb, 2'0 form cutting combs Zd at their outer edges and are provided with hooks 2'a, which engage corresponding holes 4a of a tie web 4', as is shown in FIG. 30. The tie web 4 is provided on its underside with a coupling part 4'b, which is engaged by the rotating shaft of the motor for driving the lower blade. An arched shape is enforced upon the cutter blade 2 by the engagement of the hooks Z'a with the web 4'.

FIG. 4 shows a modification of the embodiment of FIGS. 3a] to 3d. The lower blade may consist of several sectors as in FIG. 3b or may be entirely congruent with the upper blade and is angled downwardly at its edge. The angled portions Ze of the blade engage the inside of an annular flange 4", which is formed on a tie web 4. The latter is provided with a driver 4b.

The annular part 3' of FIG. 4 or the frame 3 of FIG. 1 may be formed directly on the shaver housing, as is shown in FIG. 5.

To ensure an adequate stiffness of the arched blades as well as favorable cutting angles, one of the blades, e.g., the lower blade, is provided according to FIG. 6 with cutting edges 7, which extend at least approximately at right angles to the direction of movement and consist, e.g., of elongated holes arranged in staggered rows. The other blade, e.g., the upper one, is formed with rhombic apertures 8, which have a longer diagonal extending in the direction of the cutting edges of the first-mentioned blade. As is indicated by arrows 9 in FIG. 6, this blade is formed with continuous, oblique lands, which contribute to the stiffness of the blade. On the other hand, the apertures 8 have a relatively large width transversely to the direction of movement of the lower knife so that the entrance of the hair is promoted. The co-acting cutting edges of the two blades include an acute angle in either direction of movement so that a good shearing effect is ensured. The acute angle of the rhombic holes should be at most 60 and preferably 50 or less.

According to FIG. 6, the cutting combs 1d (see FIG. 1a) are simply for-med in that the outer cutter blade is angled along the shorter diagonal of a row of rhombic apertures.

The blades of the cutter head according to the invention must be made from a material which has a uniform strength in all directions without a direction of preferential strength, good stamping qualities and a high deformability when hardened. In view of these and other requirernents, it is recommended to use beryllium copper for the blades and to provide them with a plating of hard chromium or nickel in order to improve the edge life.

What is claimed is:

1. A cutter head for a dry shaver having cutting means for short and long hair, comprising an arched flexible upper cutter blade, an arched flexible lower cutter blade movable in cutting direction relative to the upper blade, said arched upper blade having edge portions which are angled toward a concave side of said upper blade, said angled edge portions having apertures to receive projections projecting inwardly from upper blade carrier portions arranged on the outer side of said angled edge portions, the lower blade having down-turned hook elements for engagement with seats provided on a carrier for the lower blade, said interengagement imparting an arched shape at least to the central portion of the lower blade, the radius of curvature of said arched portion at its vertex being at least twice the rise of said arched portion, the contours of the arched portions of the cutter blades, when viewed in the cutting direction, being substantially congruent and said arched portions being sub stantially coextensive with the area of contact between the cutter blades, the arched portions of the lower and upper blades being perforated to form the short cutting References Cited UNITED STATES PATENTS Wimberger 30-341 Samotey 30-4392 Wright 30-43.2 X Heyek 30-4392 Heyek 30-4392 Heyek 30-341 Beisma 30-4392 Liska 30-4392 X MYRON C.

6 10/1965 Heyek 30-34.1 8/1966 Messinger et a1. 30-4391 9/1967 Loner 30-34.1 11/1960 Wahl 30-4392 9/1962 Wahl 30-4392 8/1965 Okubo 30-34.1

FOREIGN PATENTS 12/1960 France.

3/ 1960 Germany. 4/ 1941 Great Britain.

KRUSE, Primary Examiner.

US. Cl. X.R. 

